Use log.debug to dump ES 8.x _type information
Use log.debug to dump ES 8.x _type information

When using ES 8.x, `_type` metadata will not be specified due to removal
mapping of types.

ref: https://www.elastic.co/guide/en/elasticsearch/reference/current/removal-of-types.html

Signed-off-by: Hiroshi Hatake <54b742842f0d940c9715551f77be1b560ea6cc67@gmail.com>

uken/fluent-plugin-elasticsearch